Barack Obama and gun advocates slammed Senators after the Manchin-Toomey proposal failed to get 60 votes on Wednesday, accusing opponents of caving to pressure from the gun lobby.

Eight senators broke from their parties in the vote. An analysis of their votes indicates a reelection concerns were more important than fealty to gun rights’ lobbyists.

New York City Mayor Michael Bloomberg, joined the president in denouncing the vote. Bloomberg released a statement as part of Mayors Against Illegal Guns after the vote.

“Today’s vote is a damning indictment of the stranglehold that special interests have on Washington,” the group’s statement said, according to ABC News. “More than 40 U.S. senators would rather turn their backs on the 90 percent of Americans who support comprehensive background checks than buck the increasingly extremist wing of the gun lobby.”

Four Democrats broke from the majority of their party: Mark Begich of Alaska, Mark Pryor of Arkansas, Max Baucus of Montana, and Heidi Heitkamp of North Dakota. Begich, Pryor, and Baucus all face reelection in 2014 in states that Mitt Romney won in 2012—by wide margins. Heitkamp represents a similarly deep red state, but will not face an election until 2018.

Gun data and NRA membership data are not readily available. However, most states have published lists of concealed carry firearm permits, which can serve as a rough measure of gun rights support in the states. Begich represents a state with a low per capita level of permits, according to data from a Government Accountability Office 2012 report. Pryor is in a higher than average state, while Baucus represents a state with an average number. Heitkamp’s North Dakota did not provide data to the government.

Similarly, four Republicans broke from their party in their votes: The bill’s co-sponsor, Pat Toomey from Pennsylvania, John McCain, from Arizona, Mark Kirk from Illinois, and Susan Collins from Maine. Only McCain represents a state that Romney won in 2012. Collins faces reelection in 2014. Only Toomey represents a state with high per capita concealed carry permits. In fact, Kirk, in Illinois, represents a state that does not allow concealed carry, though the state legislature will change this soon.

McCain’s is the only vote out of all the eight senators who broke from their party that would be unwise from a reelection strategy.

Even looking at the money, seems to indicate that the gun rights lobby does not have a stranglehold on votes. Begich and Heitkamp received no contributions from gun rights lobbyists according to data from the Center for Responsive Politics. The data stretches back to 2007. Pryor received a grand total of $2,000 and Baucus $8,000.

McCain and Toomey dwarf those totals with $14,450 and $11,000 respectively. Collins received $3100. Kirk received $500 from gun control lobbyists, a paltry sum in an age when Senate campaigns raises tens of millions.

Even had the Democrats all held rank, the vote would have fallen two short needed to move the measure forward. Political scientists Keith Poole and Christopher Hare wrote a blog post predicting Georgia senators Saxby Chambliss and Johny Isakson would have been the next most likely Republicans to support the measure. Both represent a state that Romney only won by a 7 percent margin and with above average per capita concealed carriers.

Below is a chart that shows a full list of all Senators, their votes, how their state voted in 2012, and the number of concealed carriers per 100,000 residents.

Recent polling shows a strong partisan divide on gun control. According to an April Quinnipiac Poll, only 29 percent of Republicans support stricter gun control, while 78 percent of Democrats support it. The same poll does show an overwhelming support for increased background checks, with even 88 percent of Republicans supporting.

During an intense political campaign, a vote on this measure would certainly be used against senators like Baucus, Pryor, and Begich, all of whom are certain to face difficult reelection battles in 2014. It may have been too much of a gamble to back a measure that could easily be distorted during a campaign into something voters in their states staunchly oppose.

Democrat Harry Reid of Nevada vote against the measure due to procedural rules. Reid can bring the measure back up for vote because of his vote.

Full list of Senators on the Manchin-Toomey vote. Click to enlarge. (Corey Kane)